Cutting tool for tissue surgical resection

ABSTRACT

A cutting tool for tissue surgical resection instruments, such as electric or ultrasonic bistoury, includes a connector element ( 5 ) supported in its upstream portion by the bistoury, a thin cutting element ( 7 ) integral with the connector element ( 5 ), and forming a plane, and a guide element ( 15 ) spaced apart from the cutting element ( 7 ) by a distance (b) equal to the thickness of the tissue elements to be removed and designed, during the cutting procedure, to be urged in contact with the surface ( 1 ) thereof. The guide element ( 15 ) is located in the cutting element plane, and its surface ( 1 ) adapted to be urged in contact with the tissues is larger than the corresponding surface of the cutting element ( 7 ).

[0001] The present invention relates to a cutting tool intended for thesurgical resection of tissues and more principally to ade-epidermization.

[0002] It is known that such a surgical act, which is effected most ofthe time by plastic surgeons, consists in removing the superficial layerof the skin, taking care to respect the subjacent vascularizationfollowing its course in the dermis. This surgical act, which isparticularly delicate to carry out, is effected by using various bluntinstruments of scissors or scalpel type. This technique is delicate,particularly by reason of the difficulty that there is to ensure aremoval of the dermis which is regular in thickness.

[0003] The instruments used in the prior state of the art are not ableto ensure such a regularity of the removed dermis.

[0004] It is an object of the present invention to overcome thesedrawbacks by proposing a cutting tool for bistoury which, withoutrequiring particular skill, ensures, virtually automatically, a removalof a superficial layer of tissue which is regular in thickness.

[0005] The present invention thus has for its object a cutting toolintended for tissue surgical resection instruments, such as inparticular electric or ultrasonic bistouries, of the type comprising aconnector element which is supported in its upstream portion by thebistoury, a thin cutting element integral with the connector element,and forming a plane, and a guide element spaced apart from the cuttingelement by a distance equal to the thickness of the tissue elements tobe removed and which is designed, during the cutting procedure, to beurged in contact with the surface thereof, characterized in that theguide element is located in the cutting element plane, and its surfaceadapted to be urged in contact with the tissues is larger than thecorresponding surface of the cutting element.

[0006] The guide element and the cutting element will preferably havecross-sections which are at least partly circular and the radius ofcurvature of the guide element will be greater than that of the cuttingelement.

[0007] Furthermore, the guide element may be a cylindrical element whoseaxis will be parallel to that of the cutting element.

[0008] The guide element may be constituted by one or more rotaryelements adapted to roll on the tissues to be removed when they aredisplaced on these latter. Such rotary elements may present a certainnoteworthy coefficient of friction with respect to the tissue to beremoved, which, as has been observed, improves regularity of thedisplacement of the cutting element.

[0009] The guide element will preferably be constituted by a cylindricalelement whose axis will be parallel to that of the cutting element.

[0010] In one form of embodiment of the invention, which is simple andinexpensive to implement, the blade will be constituted by a metal wirebent to as to form a loop of substantially rectangular shape of whichone of the sides will constitute the cutting element and the oppositeside will constitute the guide element. This latter element may becoated with an insulating material.

[0011] In another form of embodiment of the invention, the cutting toolwill comprise means for adjusting the distance existing between thecutting element and the guide element, which will enable the surgeon toeffect, with the aid of the same tool, removals of differentthicknesses.

[0012] This cutting tool is intended in particular to equip an electricbistoury but it may also be used on other types of bistouries such as inparticular ultrasonic bistouries.

[0013] When the bistoury is an electric bistoury, the cutting elementwill be in electrical connection with the bistoury and the guide elementwill not be in electrical connection therewith. In that case, the guideelement may either be made of an insulating material or be made of aconducting material provided with insulating means.

[0014] It is known that de-epidermization may be effected for differentpurposes and in particular for purposes of aesthetic and reconstructivesurgery. It is also carried out in order to avoid the formation ofepidermic cysts in the event of turning-in of a musculo-cutaneous flap,in the case of a mammary reconstruction particularly when the flap isturned in under the cutaneous envelope of the breast after ablation ofthe glandular tissues. Moreover, in this same domain, it is known that,when an internal mammary prosthesis is fitted, one of the complicationswhich sometimes arises is the formation of a peri-prosthetic fibrousshell which, in the course of time, brings about a loss of suppleness ofthe breast as well as a deformation thereof. The treatment usuallycarried out consists in an exeresis of this shell by repeating theincision through which the prosthesis was fitted and which, foraesthetic reasons, is the smallest possible.

[0015] The present invention is more particularly interesting in thisdomain of surgery, since it makes it possible to ensure the exeresis ofsuch a shell in particularly easy, regular and efficient manner.

[0016] Furthermore, the present invention is particularly well adaptedto effecting resections under endoscopic control (hysteroscopy,cystoscopy) of the internal part of a hollow organ and in particular ofthe uterus, bladder or digestive tube, insofar as it allows the surgeonto be sure of not hollowing out to too great a depth.

[0017] The cutting tool according to the invention may be used withunipolar electric bistouries, but also with bipolar electric bistouries.To that end, the tool may comprise connection means making it possibleto connect, on the one hand, the cutting element to one current supplypole and, on the other hand, conducting elements close to the cuttingelement to the other supply pole.

[0018] Various forms of embodiment of the present invention will bedescribed hereinafter by way of non-limiting examples, with reference tothe accompanying drawings, in which:

[0019]FIG. 1 is a view in section of a cutting tool for electricbistoury according to the invention, which is disposed perpendicularlyto the plane of a skin surface which it is desired to de-epidermize.

[0020]FIG. 1a is a view in transverse section of the cutting tool shownin FIG. 1 along line Ia-Ia thereof.

[0021]FIG. 2 is a partial longitudinal sectional view along a planeperpendicular to a skin surface to be de-epidermized, of a variantembodiment of the invention in which the thickness of the tissues to beremoved is adjustable.

[0022]FIG. 3 is a view on a smaller scale of a cutting tool for bistouryaccording to the invention, of non-adjustable type.

[0023]FIG. 3a is a view in section of the tool shown in FIG. 3 alongline IIIa-IIIa thereof.

[0024]FIG. 3b is an enlarged partial sectional view of the tool shown inFIG. 3a.

[0025]FIG. 4 is a view in perspective of a variant embodiment of acutting tool according to the invention.

[0026]FIG. 4a is a schematic view in section of another example ofapplication of the cutting tool for electric bistoury according to theinvention shown in FIG. 4.

[0027]FIG. 5 is a partial view in perspective of a cutting toolaccording to the invention intended for use on a bipolar bistoury.

[0028]FIGS. 1 and 1a show views in section, along a plane perpendicularto a skin surface 1, of a cutting tool 3 which is intended to beconnected to an electric bistoury (not shown in the drawing). Thiscutting tool 3 thus comprises a rod 5 of stainless steel wire which isbent in its lower part so as to form a perpendicular arm 7. This arm 7has a length a which corresponds to the working width of the tool 3. Thearm 7 terminates in a 90° bend extending in a second arm 9 parallel tothe rod 5 and itself terminating in another right-angled bend so as toform an arm 11 parallel to the arm 7 and of the same length a as thelatter. The end of the arm 11 comes into contact with the rod 5 and isfixed thereon, for example by means of welding spots 13. A guide element15, constituted by an insulating and rigid cylinder, is threaded on thearm 11 and is mounted to rotate thereon. This guide element 15 definesbetween its periphery and the upper face of the arm 7 a space ofdistance b which corresponds, as explained hereinafter, to the thicknessof the tissue which it is desired to remove.

[0029] The end of the rod 5 is connected to means, not shown in thedrawing, for fixation of an electric bistoury of unipolar type.

[0030] Under these conditions, the bistouri according to the inventionoperates as indicated hereinafter. The means for supplying current tothe electric bistoury being connected, the surgeon brings the arm 7 intocontact with the patient's skin and drives his cutting tool until theguide element 15 comes into contact with the upper surface 1 of theskin. It then remains for the surgeon to displace the bistoury in thedirection V so as to create, during this displacement, a cut-out 17 inthe tissues, thus forming a flap of epidermis 19 of regular thickness b.

[0031] In an interesting form of embodiment of the invention, thedistance b is adjustable, which makes it possible for the surgeon to usethe same cutting tool for various interventions.

[0032]FIG. 2 shows for example such a form of embodiment. The cuttingtool 3 is thus constituted by a rod 20 which is connected to thebistoury by means not shown in the drawing, and which comprises athreaded zone 22 on which is screwed an adjusting wheel 24. This wheelcomprises an inner chamber in which is disposed a bush 25 which isthreaded on the rod 20 and which comprises in its upper part a flange 26which has the effect of connecting it in translation with the wheel 24while leaving it free to rotate with respect thereto. The lower part ofthe rod 20 extends downwardly by a portion of arm Sa which is made ofstainless steel wire and which is bent at 90° in order to form a part 7a intended to constitute the cutting element of the tool. A guideelement 1 Sa is constituted by a rigid cylinder of plastics materialwhich is mounted for rotation about two end bosses 27 which are mountedfor rotation in two corresponding recesses provided in the bush 25.

[0033] For reasons of simplification, only the left-hand half of thecutting tool 3 has been shown in FIG. 2, the other, right-hand halfbeing identical thereto.

[0034] In order to adjust the thickness b of the tissue to be removed,it will suffice for the practitioner to screw or unscrew the wheel 24 onthe threaded part 22 of the rod 20, which will have the effect ofdisplacing it in the longitudinal direction of this rod and consequentlyof moving the guide element 15 a towards or away from the cuttingelement 7 a of the tool 3 depending on the direction of rotation of thewheel 24.

[0035] The outer surface of the guide element will advantageouslypresent slight roughness, intended to create a sufficient adherencebetween its outer surface and the surface 1 of the skin, so that, duringthe displacement V, the guide element does not slide on the surface ofthe skin but rolls thereon. In fact, it has been observed that, by thusimproving the adherence of the guide element on the surface of the skin,the regularity of the displacement of the cutting element was improvedat the same time. The roughness of the outer surface of the guideelement may be produced by any means, whether it be by sand-blasting orby granulometry made at moulding, etc.

[0036] In a simplified form of embodiment of the invention shown in FIG.3, the cutting element is constituted by a stainless steel wire 29 whichis supported by a bistoury head 32 and which is wound so as to form aloop. In this form of embodiment of the invention, the thickness b ofthe flap of removed tissue is fixed. To that end, the opposite sides 5 aof the loop and the side 7 a form the cutting element. The side 15 bopposite to side 7 a constitutes the guide element and is consequentlycoated with an insulating material. This same insulating material isalso deposited over a length l of the wire 29.

[0037] The cross-section of the guide element 15 b is moon-shaped, theconcavity being oriented upwardly and the radius R of its base beingmuch greater than the radius r of the cutting element. Under theseconditions, the outer surface of this guide element capable of cominginto contact with the tissues 1 is much larger than that of the cuttingelement 7 a, which has the effect of promoting its guiding and smoothdisplacement over the tissues 1.

[0038] This form of embodiment is particularly interesting due to itslow cost price which will allow the practitioner to have available a setof cutting tools of various width a and thickness b appropriate for thedifferent interventions that he wishes to carry out.

[0039] Of course, in certain forms of embodiment of the invention, thesupport rod or rods 5 or 29 do not necessarily lie in the plane formedby the cutting element and the guide element, and may form any anglewith said plane. In particular, they may be perpendicular thereto asshown in FIGS. 4 and 4a.

[0040] Thus, by way of example, when it is desired to effect a resectionof a peri-prosthetic fibrous shell 36 which may be formed in the courseof time when an internal mammary prosthesis is fitted, and which bringsabout a loss of suppleness of the breast as well as a deformationthereof, an angle of 90° is made between said plane and the rod 29. Thisallows the cutting element of the bistouri to be introduced through anincision 38 of small dimensions and to eliminate this shell 36 by adisplacement substantially in the direction V′ of the cutting tool 3.Such a cutting tool may also be used in combination with an electricbistoury operating in bipolar mode.

[0041]FIG. 5 thus shows a cutting tool 3 comprising two metallic supportarms 40 which terminate in two insulating studs 42 made of ceramics, atthe base of which is fixed a U-shaped metallic cutting element 7 a.Between the two studs 42 is disposed a guide element 15 a constituted byan insulating cylinder mounted for rotation about its longitudinal axis.In this form of embodiment, one of the poles A for electrical energysupply is connected to the arms 40 and the other pole B is connected tothe cutting element 7 a, by two insulated conductors 37 which passthrough the arms 40 and which are connected to each of the ends of thecutting element 7 a.

[0042] Such a cutting tool may be used in particular for variousapplications and in particular for effecting endoscopic resections in asaline medium.

1. Cutting tool intended for tissue surgical resection instruments, suchas in particular electric or ultrasonic bistouries, of the typecomprising a connector element (5, 5 a, 29) which is supported in itsupstream portion by the bistoury (32), a thin cutting element (7, 7 a)integral with the connector element (5, 5 a, 29), and forming a plane,and a guide element (15, 15 a, 15 b) spaced apart from the cuttingelement (7, 7 a) by a distance (b) equal to the thickness of the tissueelements to be removed and which is designed, during the cuttingprocedure, to be urged in contact with the surface (1) thereof,characterized in that the guide element (15, 15 a, 15 b) is located inthe cutting element plane, and its surface (1) adapted to be urged incontact with the tissues is larger than the corresponding surface of thecutting element (7, 7 a).
 2. Cutting tool according to claim 1,characterized in that the guide element (15, 15 a, 15 b) and the cuttingelement (7, 7 a) have cross-sections which are at least partly circularand the radius of curvature (R) of the guide element (15, 15 a, 15 b) isgreater than that (r) of the cutting element (7, 7 a).
 3. Cutting toolaccording to claim 2, characterized in that the guide element (15, 15 a15 b) is a cylindrical element whose axis is parallel to that of thecutting element (7, 7 a).
 4. Cutting tool according to one of thepreceding claims, characterized in that the guide element (15, 15 a) isconstituted by at least one rotary element adapted to rotate when it isdisplaced over the surface (1) of the tissues to be removed.
 5. Cuttingtool according to claim 4, characterized in that the outer surface ofthe rotary element (15, 15 a) presents a noteworthy coefficient offriction with respect to the tissues to be removed.
 6. Cutting toolaccording to one of the preceding claims, characterized in that thecutting element (7, 7 a) is in electrical connection with the bistoury(32), and the guide element (15, 15 a, 15 b) is not in electricalconnection therewith.
 7. Cutting tool according to claim 6,characterized in that the guide element (15, 15 a, 15 b) is constitutedby an insulating material.
 8. Cutting tool according to one of thepreceding claims, characterized in that it is constituted by a metallicwire forming a loop of substantially rectangular shape, of which one ofthe sides (7 a) constitutes the cutting element and the opposite side(15 b) constitutes the guide element.
 9. Cutting tool according to oneof the preceding claims, characterized in that it comprises means (24,25) for adjusting the distance (b) which exists between the cuttingelement (7 a) and the guide element (15 a, 15 b).
 10. Cutting toolaccording to one of the preceding claims, characterized in that it isprovided with a supply of current of bipolar type.